CVE-2018-1000824
📋 TL;DR
MegaMek versions before 0.45.1 contain a Java deserialization vulnerability in the Object Stream Connection component that allows remote attackers to execute arbitrary code. This affects all users running vulnerable versions of the MegaMek game software. Attackers can exploit this to take full control of affected systems.
💻 Affected Systems
- MegaMek
📦 What is this software?
Megamek by Megamek
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, and lateral movement within networks.
Likely Case
Remote code execution resulting in installation of malware, cryptocurrency miners, or ransomware on vulnerable systems.
If Mitigated
No impact if patched to version 0.45.1 or later, or if network access is properly restricted.
🎯 Exploit Status
Public exploit code exists and the vulnerability is easily exploitable via network connections to the game server.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v0.45.1 and later
Vendor Advisory: https://github.com/MegaMek/megamek/issues/1162
Restart Required: Yes
Instructions:
1. Download MegaMek v0.45.1 or later from official sources. 2. Stop the MegaMek application. 3. Replace the installation with the new version. 4. Restart the application.
🔧 Temporary Workarounds
Network Isolation
allBlock network access to MegaMek servers using firewall rules
# Linux iptables example: iptables -A INPUT -p tcp --dport [MegaMek port] -j DROP
# Windows firewall: New-NetFirewallRule -DisplayName "Block MegaMek" -Direction Inbound -Protocol TCP -LocalPort [MegaMek port] -Action Block
🧯 If You Can't Patch
- Disable network functionality and run MegaMek in offline/local-only mode
- Implement strict network segmentation to isolate MegaMek systems from critical infrastructure
🔍 How to Verify
Check if Vulnerable:
Check the MegaMek version number in the application or configuration files. If version is below 0.45.1, the system is vulnerable.Check Version:
# On Linux/macOS: java -jar megamek.jar --version or check megamek.log
# On Windows: Check Help → About in the applicationVerify Fix Applied:
Verify the installed version is 0.45.1 or higher. Check that the application runs without errors after update.📡 Detection & Monitoring
Log Indicators:
- Unusual Java deserialization errors in logs
- Unexpected network connections to/from MegaMek ports
- Suspicious Java process spawning
Network Indicators:
- Malformed serialized objects sent to MegaMek ports
- Unexpected outbound connections from MegaMek hosts
SIEM Query:
source="megamek.log" AND ("deserialization" OR "ObjectInputStream" OR "remote code")